Research On Direct Reduction Of Vanadium-titanium Magnetite Concentrate

This paper studys the weak reduction and magnetic separation of vanadium-titanium magnetite concentrate in order to achieve the comprehensive utilization of vanadium-titanium iron. Thermodynamic principles, modern analysis technologies such as SEM and X-ray diffraction are applied. The factors of weak reduction process includes reducing agent, reducting temperature, reducting time and dosage of reducing agent. On the above basis, the magnetic separation of reducting product from vanadium-titanium magnetite concentrate is studied.The following conclusions can be drawn from the weak reduction of vanadium-titanium magnetite:1. Reduction temperature and time are main factors of the elemental iron content, total iron content, metallization and size of metallic iron. Reduction in the total iron content of the product, metal iron, the metal generally consistent with the reduction rate of temperature increase and increased with increasing reduction time. The reducing agent has little effect. The modified reducing agent X is much better than graphite.2. SEM analysis shows that the metallic iron particles in the product begin to grow and merger with the reduction time, which increase the possibility of dissociation between the matrix phase and the metal iron phase. With the reduction temperature increased, metallic iron particles is becoming larger in volume and the boundaries between each phase and the phase types of product are becoming distinct. The diffraction intensity of the metal iron phase increased. When the dosage of graphite is15%, the reduction temperature is1150℃, reduction time is3hours, vanadium and titanium components would be enriched in magnetic separation tailings, Si components is mainly distributing in the silicate phase and impurity phase, and the iron is enriched in iron-rich phase.Results of magnetic separation are as follows:1. The products of using graphite as reducing agent can be separated by magnetic and basically achieve the separation of iron from titanium and vanadium, but the result is not satified,thus the modified reducing agent X is studied.2. The results of reduction and magnetic separation is better when modified reducing agent X is applied,and the reduction temperature is1150℃, reduction time is3hours. Magnetic separation results are as follows:the particle size is<48μm and magnetic current intensity is1.75A, the concentration of mine is3%, the total iron content in the magnetic concentrate is84.82%, and recovery rate is93.78%;The content of V2O5in the tailings is3.7671%, and recovery rate is78.68%; The content of TiO2in the tailings is55.86%, and recovery rate is75.67%, which indicated that the iron,vanadium and titanium can be separated succefully.